Light sources such as candles and gel pots are commonly used as decorative light sources, and to disperse fragrances. These light sources include a wick extending from the candle or gel. A flame at the end of the wick is sustained by wax or gel that has been melted by the heat of the flame. In particular, the heat of the flame melts a small pool of the candle body material around the base of the exposed portion of the wick. This molten material is then drawn up through and along the wick by capillary action to fuel the flame. Candles and gel pots may also be used to effectively disperse fragrance molecules included in the wax or gel. Such fragrance is dispersed when it is volatilized from the liquid pool into the surrounding air.
Conventional oil lamps differ from candles and gel pots in that the oil is held in a container with no access to the outside except through the wick, which protrudes from the container through a wick aperture. Such lamps are typically filled through the wick aperture with the wick temporarily removed, or through a filling hole that can be sealed or plugged prior to lighting the oil lamp. When lit, a flame on the end of the wick outside of the container is sustained by oil rising through the wick by capillary action. The closed container has several advantages. For example, the risk of a spill is reduced. Also, there is that oil within the closed container will be accidentally ignited. However, the closed container also prevents fragrance molecules volatilized from the oil from escaping the container into the surrounding air. As a result, conventional oil lamps do not effectively disperse fragrance. Although fragrance molecules may rise through the wick to the flame, the amount of such molecules that rise through the wick and survive combustion are not sufficient to effectively disperse fragrance.
Oils for use in lamps often contains fragrance molecules. However, the purpose of the fragrance is to entice the consumer at the point of sale, and to suppress unpleasant odors associated with certain types of oil, such as kerosene. The fragrance is not dispersed during burning in a conventional oil burning lamp.
Because the oil used in oil burning lamps is liquid at room temperature, conventional oil lamps are not designed to effectively heat oil in the container. Indeed, such heating may have been undesirably viewed as creating a higher risk of uncontrolled fires. Some conventional wicks do include metal cores for the purpose of supporting the wick. However, these cores may be too small to effectively conduct heat from the flame to the oil. Moreover, they do not have a significant area exposed to either the heat of the flame or the oil within the lamp, because they are encased by the wick, which restricts their ability to conduct heat from the wick to the oil. Such cores were previously made of lead. However, due to health concerns associated with lead, zinc is commonly used today.
Conventional oil lamps may be made of a variety of substances, including glass and ceramic. Glass is generally preferred for its decorative qualities.